1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 22 /* 23 * Copyright (c) 1988 AT&T 24 * All Rights Reserved 25 * 26 * Copyright 2006 Sun Microsystems, Inc. All rights reserved. 27 * Use is subject to license terms. 28 */ 29 #pragma ident "%Z%%M% %I% %E% SMI" 30 31 /* 32 * ld -- link/editor main program 33 */ 34 #include <sys/types.h> 35 #include <sys/mman.h> 36 #include <string.h> 37 #include <stdio.h> 38 #include <locale.h> 39 #include <stdarg.h> 40 #include <debug.h> 41 #include "msg.h" 42 #include "_libld.h" 43 44 /* 45 * A default library search path is used if one was not supplied on the command 46 * line. Note: these strings can not use MSG_ORIG() since they are modified as 47 * part of the path processing. 48 */ 49 #if defined(_ELF64) 50 static char def_Plibpath[] = "/lib/64:/usr/lib/64"; 51 #else 52 static char def_Plibpath[] = "/usr/ccs/lib:/lib:/usr/lib"; 53 #endif 54 55 /* 56 * A default elf header provides for simplifying diagnostic processing. 57 */ 58 static Ehdr def_ehdr = { { ELFMAG0, ELFMAG1, ELFMAG2, ELFMAG3, 59 M_CLASS, M_DATA }, 0, M_MACH, EV_CURRENT }; 60 61 /* 62 * The main program 63 */ 64 int 65 ld_main(int argc, char **argv) 66 { 67 char *sgs_support; /* SGS_SUPPORT environment string */ 68 Half etype; 69 int suplib = 0; 70 Ofl_desc *ofl; 71 72 /* 73 * Initialize signal handlers, and output file variables. Establish a 74 * default output ELF header to satisfy diagnostic requirements. 75 */ 76 if ((ofl = libld_calloc(1, sizeof (Ofl_desc))) == 0) 77 return (1); 78 79 ofl->ofl_dehdr = &def_ehdr; 80 81 ld_init(ofl); 82 83 /* 84 * Build up linker version string 85 */ 86 if ((ofl->ofl_sgsid = (char *)libld_calloc(MSG_SGS_ID_SIZE + 87 strlen(link_ver_string) + 1, 1)) == NULL) 88 return (1); 89 (void) strcpy(ofl->ofl_sgsid, MSG_ORIG(MSG_SGS_ID)); 90 (void) strcat(ofl->ofl_sgsid, link_ver_string); 91 92 /* 93 * Argument pass one. Get all the input flags (skip any files) and 94 * check for consistency. After this point any map file processing 95 * would have been completed and the entrance criteria and segment 96 * descriptor lists will be complete. 97 */ 98 if (ld_process_flags(ofl, argc, argv) == S_ERROR) 99 return (1); 100 if (ofl->ofl_flags & FLG_OF_FATAL) { 101 eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_ARG_FLAGS)); 102 return (1); 103 } 104 105 /* 106 * At this point a call such as ld -V is considered complete. 107 */ 108 if (ofl->ofl_flags1 & FLG_OF1_DONE) 109 return (0); 110 111 /* 112 * Determine whether any support libraries been loaded (either through 113 * the SGS_SUPPORT environment variable and/or through the -S option). 114 * By default the support library libldstab.so.1 is loaded provided the 115 * user hasn't specified their own -S libraries. 116 */ 117 #if defined(_LP64) 118 if ((sgs_support = getenv(MSG_ORIG(MSG_SGS_SUPPORT_64))) == NULL) 119 #else 120 if ((sgs_support = getenv(MSG_ORIG(MSG_SGS_SUPPORT_32))) == NULL) 121 #endif 122 sgs_support = getenv(MSG_ORIG(MSG_SGS_SUPPORT)); 123 124 if (sgs_support && (*sgs_support != '\0')) { 125 const char *sep = MSG_ORIG(MSG_STR_COLON); 126 char *lib; 127 char *lasts; 128 129 DBG_CALL(Dbg_support_req(ofl->ofl_lml, sgs_support, 130 DBG_SUP_ENVIRON)); 131 if ((lib = strtok_r(sgs_support, sep, &lasts)) != NULL) { 132 do { 133 if (strcmp(lib, 134 MSG_ORIG(MSG_FIL_LIBSTAB)) == 0) { 135 if (suplib++) 136 continue; 137 } 138 if (ld_sup_loadso(ofl, lib) == S_ERROR) 139 return (ld_exit(ofl)); 140 141 } while ((lib = strtok_r(NULL, sep, &lasts)) != NULL); 142 } 143 } 144 if (lib_support.head) { 145 Listnode *lnp; 146 char *lib; 147 148 for (LIST_TRAVERSE(&lib_support, lnp, lib)) { 149 DBG_CALL(Dbg_support_req(ofl->ofl_lml, lib, 150 DBG_SUP_CMDLINE)); 151 if (ld_sup_loadso(ofl, lib) == S_ERROR) 152 return (ld_exit(ofl)); 153 } 154 } else { 155 if (suplib == 0) { 156 DBG_CALL(Dbg_support_req(ofl->ofl_lml, 157 MSG_ORIG(MSG_FIL_LIBSTAB), DBG_SUP_DEFAULT)); 158 if (ld_sup_loadso(ofl, MSG_ORIG(MSG_FIL_LIBSTAB)) == 159 S_ERROR) 160 return (ld_exit(ofl)); 161 } 162 } 163 164 DBG_CALL(Dbg_ent_print(ofl->ofl_lml, ofl->ofl_dehdr->e_machine, 165 &ofl->ofl_ents, (ofl->ofl_flags & FLG_OF_DYNAMIC))); 166 DBG_CALL(Dbg_seg_list(ofl->ofl_lml, ofl->ofl_dehdr->e_machine, 167 &ofl->ofl_segs)); 168 169 /* 170 * The objscnt and soscnt variables were used to estimate the expected 171 * input files, and size the symbol hash buckets accordingly. Reset 172 * these values now, so as to gain an accurate count from pass two, for 173 * later statistics diagnostics. 174 */ 175 ofl->ofl_objscnt = ofl->ofl_soscnt = 0; 176 177 /* 178 * Determine whether we can create the file before going any further. 179 */ 180 if (ld_open_outfile(ofl) == S_ERROR) 181 return (ld_exit(ofl)); 182 183 /* 184 * If the user didn't supply a library path supply a default. And, if 185 * no run-path has been specified (-R), see if the environment variable 186 * is in use (historic). Also assign a default starting address. 187 * Don't use MSG_ORIG() for these strings, they're written to later. 188 */ 189 if (Plibpath == NULL) 190 Plibpath = def_Plibpath; 191 192 if (ofl->ofl_rpath == NULL) { 193 char *rpath; 194 if (((rpath = getenv(MSG_ORIG(MSG_LD_RUN_PATH))) != NULL) && 195 (strcmp((const char *)rpath, MSG_ORIG(MSG_STR_EMPTY)))) 196 ofl->ofl_rpath = rpath; 197 } 198 if (ofl->ofl_flags & FLG_OF_EXEC) 199 ofl->ofl_segorigin = M_SEGM_ORIGIN; 200 201 /* 202 * Argument pass two. Input all libraries and objects. 203 */ 204 if (ld_lib_setup(ofl) == S_ERROR) 205 return (ld_exit(ofl)); 206 207 /* 208 * Call ld_start() with the etype of our output file and the 209 * output file name. 210 */ 211 if (ofl->ofl_flags & FLG_OF_SHAROBJ) 212 etype = ET_DYN; 213 else if (ofl->ofl_flags & FLG_OF_RELOBJ) 214 etype = ET_REL; 215 else 216 etype = ET_EXEC; 217 218 ld_sup_start(ofl, etype, argv[0]); 219 220 /* 221 * Process all input files. 222 */ 223 if (ld_process_files(ofl, argc, argv) == S_ERROR) 224 return (ld_exit(ofl)); 225 if (ofl->ofl_flags & FLG_OF_FATAL) { 226 eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_ARG_FILES), 227 ofl->ofl_name); 228 return (ld_exit(ofl)); 229 } 230 231 ld_sup_input_done(ofl); 232 233 /* 234 * If there were any partially initialized symbol, 235 * do preparation works. 236 */ 237 if (ofl->ofl_ismove.head != 0) { 238 if (ld_sunwmove_preprocess(ofl) == S_ERROR) 239 return (ld_exit(ofl)); 240 } 241 242 /* 243 * Before validating all symbols count the number of relocation entries. 244 * If copy relocations exist, COMMON symbols must be generated which are 245 * assigned to the executables .bss. During sym_validate() the actual 246 * size and alignment of the .bss is calculated. Doing things in this 247 * order reduces the number of symbol table traversals required (however 248 * it does take a little longer for the user to be told of any undefined 249 * symbol errors). 250 */ 251 if (ld_reloc_init(ofl) == S_ERROR) 252 return (ld_exit(ofl)); 253 254 /* 255 * Now that all symbol processing is complete see if any undefined 256 * references still remain. If we observed undefined symbols the 257 * FLG_OF_FATAL bit will be set: If creating a static executable, or a 258 * dynamic executable or shared object with the -zdefs flag set, this 259 * condition is fatal. If creating a shared object with the -Bsymbolic 260 * flag set, this condition is simply a warning. 261 */ 262 if (ld_sym_validate(ofl) == S_ERROR) 263 return (ld_exit(ofl)); 264 265 if (ofl->ofl_flags1 & FLG_OF1_OVRFLW) { 266 eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_ARG_FILES), 267 ofl->ofl_name); 268 return (ld_exit(ofl)); 269 } else if (ofl->ofl_flags & FLG_OF_FATAL) { 270 eprintf(ofl->ofl_lml, ERR_FATAL, MSG_INTL(MSG_ARG_SYM_FATAL), 271 ofl->ofl_name); 272 return (ld_exit(ofl)); 273 } else if (ofl->ofl_flags & FLG_OF_WARN) 274 eprintf(ofl->ofl_lml, ERR_WARNING, MSG_INTL(MSG_ARG_SYM_WARN)); 275 276 /* 277 * Generate any necessary sections. 278 */ 279 if (ld_make_sections(ofl) == S_ERROR) 280 return (ld_exit(ofl)); 281 282 /* 283 * Now that all sections have been added to the output file, check to 284 * see if any section ordering was specified and if so give a warning 285 * if any ordering directives were not matched. 286 * Also, if SHF_ORDERED sections exist, set up sort key values. 287 */ 288 ld_sec_validate(ofl); 289 290 /* 291 * Having collected all the input data create the initial output file 292 * image, assign virtual addresses to the image, and generate a load 293 * map if the user requested one. 294 */ 295 if (ld_create_outfile(ofl) == S_ERROR) 296 return (ld_exit(ofl)); 297 298 if (ld_update_outfile(ofl) == S_ERROR) 299 return (ld_exit(ofl)); 300 if (ofl->ofl_flags & FLG_OF_GENMAP) 301 ld_map_out(ofl); 302 303 /* 304 * Build relocation sections and perform any relocation updates. 305 */ 306 if (ld_reloc_process(ofl) == S_ERROR) 307 return (ld_exit(ofl)); 308 309 #if defined(__x86) && defined(_ELF64) 310 /* 311 * Fill in contents for Unwind Header 312 */ 313 if (populate_amd64_unwindhdr(ofl) == S_ERROR) 314 return (ld_exit(ofl)); 315 #endif 316 /* 317 * Finally create the files elf checksum. 318 */ 319 if (ofl->ofl_checksum) 320 *ofl->ofl_checksum = (Xword)elf_checksum(ofl->ofl_elf); 321 322 /* 323 * We're done, so make sure the updates are flushed to the output file. 324 */ 325 if ((ofl->ofl_size = elf_update(ofl->ofl_welf, ELF_C_WRITE)) == 0) { 326 eprintf(ofl->ofl_lml, ERR_ELF, MSG_INTL(MSG_ELF_UPDATE), 327 ofl->ofl_name); 328 return (ld_exit(ofl)); 329 } 330 331 ld_sup_atexit(ofl, 0); 332 333 DBG_CALL(Dbg_statistics_ld(ofl)); 334 335 /* 336 * For performance reasons we don't actually free up the memory we've 337 * allocated, it will be freed when we exit. 338 * 339 * But the below line can be uncommented if/when we want to measure how 340 * our memory consumption and freeing are doing. We should be able to 341 * free all the memory that has been allocated as part of the link-edit 342 * process. 343 * 344 * ofl_cleanup(ofl); 345 */ 346 return (0); 347 } 348 349 /* 350 * Cleanup an Ifl_desc. 351 */ 352 static void 353 ifl_list_cleanup(List *ifl_list) 354 { 355 Listnode *lnp; 356 Ifl_desc *ifl; 357 358 for (LIST_TRAVERSE(ifl_list, lnp, ifl)) 359 if (ifl->ifl_elf) 360 (void) elf_end(ifl->ifl_elf); 361 ifl_list->head = 0; 362 ifl_list->tail = 0; 363 } 364 365 /* 366 * Cleanup all memory that has been dynamically allocated during libld 367 * processing and elf_end() all Elf descriptors that are still open. 368 */ 369 void 370 ld_ofl_cleanup(Ofl_desc *ofl) 371 { 372 Ld_heap *chp, *php; 373 Ar_desc *adp; 374 Listnode *lnp; 375 376 ifl_list_cleanup(&ofl->ofl_objs); 377 ifl_list_cleanup(&ofl->ofl_sos); 378 379 for (LIST_TRAVERSE(&ofl->ofl_ars, lnp, adp)) { 380 Ar_aux *aup; 381 Elf_Arsym *arsym; 382 383 for (arsym = adp->ad_start, aup = adp->ad_aux; 384 arsym->as_name; ++arsym, ++aup) { 385 if ((aup->au_mem) && (aup->au_mem != FLG_ARMEM_PROC)) { 386 (void) elf_end(aup->au_mem->am_elf); 387 388 /* 389 * Null out all entries to this member so 390 * that we don't attempt to elf_end() it again. 391 */ 392 ld_ar_member(adp, arsym, aup, 0); 393 } 394 } 395 (void) elf_end(adp->ad_elf); 396 } 397 398 (void) elf_end(ofl->ofl_elf); 399 (void) elf_end(ofl->ofl_welf); 400 401 for (chp = ld_heap, php = 0; chp; php = chp, chp = chp->lh_next) { 402 if (php) 403 (void) munmap((void *)php, 404 (size_t)php->lh_end - (size_t)php); 405 } 406 if (php) 407 (void) munmap((void *)php, (size_t)php->lh_end - (size_t)php); 408 409 ld_heap = 0; 410 } 411